Thread guide for sewing machines

ABSTRACT

A thread guide having self-threading means which allow for quick threading without actually passing a thread endwise through an opening in the guide. The guide comprises a post mounted on a sewing machine and a hook shaped wire keeper secured in the post whereby the thread is slid against an outside portion of the keeper into a thread accommodating slot formed in the post where it is retained by the keeper.

United States Patent Robert M. Du Ross Homer, N.Y.

Jan. 6, 1969 Jan. 5, 1971 The Singer Company New York, N.Y.

a corporation of New Jersey lnventor Appl. No. Filed Patented Assignee THREAD GUIDE FOR SEWING MACHINES 2 Claims, 4 Drawing Figs.

U.S. Cl 242/157, 1 12/218 Int. Cl B65h 57/04 Field of Search 1 12/218,

[56] References Cited UNITED STATES PATENTS 2,688,294 9/1954 Mc Cloud 112/218 3,210,881 10/1965 Wilson 242/157X 3,276,719 10/1966 Stetz 242/157 3,381,641 5/1968 Bialy et al 112/218 FOREIGN PATENTS 452,607 11/1927 Germany 242/157 Primary Examiner-H. Hampton Hunter Alrorneys-Marshal1 J. Breen, Chester A. Williams, Jr. and

Robert E. Smith ABSTRACT: A thread guide having self-threading means which allow for quick threading without actually passing a thread endwise through an opening in the guide. The guide comprises a post mounted on a sewing machine and a hook shaped wire keeper secured in the post whereby the thread'is slid against an outside portion of the keeper into a thread accommodating slot formed in the post where it is retained by the keeper.

PATENTE U JAN 5197:

I INVENTOR.

M. uass WITNESS mum )n oawfl THREAD GUIDE FOR SEWING MACHINES BACKGROUND OF THE INVENTION Thread guides for sewing machines are well known, particularly those that are mounted on the, bracket arm top of the sewing machine to direct the needle thread from the supply spool to the stitch forming instrumentalities as shown in U.S. Pat. Nos. 3,l22,l l3 and 3,381,641. Each of the above patents discloses a thread guiding post having an'aperture in the form of an eyelet through which an endof the thread must be passed when the sewing machine is being threaded.

SUMMARY OF THE INVENTION This invention relates to a thread guide for a sewing machine, and more particularly, to a-novel self-threading thread guide in which the formation of the guide itself facilitates the threading thereof, eliminating to a considerable extent the eye strain and the other inconveniences occasioned by the necessity of passing a thread through a closed eyelet in the conventional fashion. The thread guide is mounted on the bracket arm top or the top cover plate of the sewing machine to direct the needle thread from the supply spool to the stitch forming instrumentalities.

One object of this invention is to provide a thread guide of the above character wherein the thread may be admitted to the the guide laterally and retained positively against accidental removal therefrom.

Another object of this invention is to provide a simple and efficient thread guide which may be readily attached to the arm top or top cover plate of the sewing machine in proximity to the supporting means for the supply spool.

Still another object of this invention is to provide a thread guide which will operate to effectually guide the thread without undue frictional resistance and in a manner to prevent snagging and breaking of the thread.

BRIEF DESCRIPTION OF THEDRAWINGS Having in mind the above and othe'robjects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set for forth in such detail as to enable those skilled in the art a readily to understand the function, operation, construction and advantages of it, when read in conjunction with the accompanying drawings in which: FIG. 1 represents a side elevational view of a portion of the top cover plate of a sewing machine casing with portions broken away and showing a thread guide of the present invention applied thereto:

FIG. 2 represents an enlarged top guide of this invention: V

FIG. 3 represents a further enlarged side elevational view of the thread guide of this invention: and.

FIG. 4 is a cross-sectional view of the thread guide taken substantially along line 4-4 of FIG. 3.-

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, 11 indicates a portion of the top cover plate of a sewing machine casing which may be formed with a central depression 12. Toward one end of the depression rises a standard 13 to which is affixed one end of a cylindrical spool pin 14, the free end preferably being rounded.

The spool pin 14 is adapted to accommodate a spool of thread, such as spool 16, from which the thread T is directed over an edge of the unwinding member 15 toward the sewing machine stitch forming instrumentalities through a selfthreading thread guide 1 of this in invention affixed on the top cover plate 11.

It is conventional in sewing machine construction to provide a thread guide having an aperture in the form of an eyelet through which an end of the thread must be passed when the sewing machine is being threaded-This conventional thread plan'view of the thread guide has many disadvantages such as requiring an operator to locate the end of the thread, usually requiring an operator to use both hands, one hand to push the thread through the aperture from one side and the other hand to pull the thread through from the other side, and requiring. the sewing machine to be rethreaded in cases where the thread guide has not been threaded by mistake of the operator. Also, operators with poor vision find it difficult to thread an eyelet. The thread guide of the present invention allows for quick self-threading with none of the above disadvantages.

As illustrated in FIGS. 2 and 3 the thread guide 1 of this invention includes a keeper 2 and a post 3. The keeper 2, which may be formed from a wire or a rod, has a hook 21 on one end. The keeper 2 may be made from any suitable material, such as metal or plastic, the former being preferred. The post 3', which is molded, may also be made from any suitable material, such as metal or plastic, the latter being preferred.

The bottom surface 31 of the post. 3 has a contour which matches the surface of the top cover plate 11 to which the post 3 is attached. A headed screw 17, which-extends through the top cover plate 11 into a thread hole 35 in the bottom surface 31 of the post 3, fastens the post 3 to the top cover plate 11. A projection 36 on the bottom surface 31', which is adapted to fit into a locating hole (not shown) in the top cover plate 11, acts to position the post 3 relative to the spool 16 and prevents the post 3 from rotating once the screw 17 is tightened. The sides of the post 3 are tapered towards each other, being widest near the bottom surface 31.

. The top portion of the post 3 is bifurcated forming an up wardly open thread accommodating aperture or slot 32. A groove 33 is formed in one sidewall of the slot 32 and a hole 34 is formed in the top portion of the post 3 adjacent the opposite sidewall. The straight portion 22 of the keeper 2 is press fit into the hole 34 with the free end of the hook 21 extending into groove 33, as shown in FIG. 4, so that the hook 21 spans the slot 32. The space between the hook 21 and the sidewall of the groove 33 is greater than the thickness of the thread T to facilitate the movement of the thread T therethrough.

As shown in FIG. 3, the outer surface of the hook 21 is not continuous with the outer surface of the post 3, so that substantially a notch 37 is formed on the top portion of the thread guide 1. The notch 37 positions the thread T with respect to the groove 33 to aid in directing the thread T into the groove 33. The opposite outer surface of the keeper 2 adjacent the hole 34 is-substantially continuous with the outer surface of the post 3, so that if an operator attempts to thread the thread guide 1 on the wrong side, the thread'T will not be retained and therefore will just slide off the post 3; The thread guide 1 could be positioned on the top cover plate 11 with the notch 37 facing either away from or towards the operator, the latter being preferred as shown in FIG. 1. v

It has been found that by positioning the thread guide 1 on the top cover plate 11 with the slot 32in alignment axially with the spool pin 14, the thread spool unwinder 15 permits the thread T to be directed from the spool 16 in a generally axial direction. A proper thread flow is thereby achieved without undesirable spool rotation and accompanying resistance to unwinding, snagging and breaking.

To thread the thread guide 1, the operator either forms thethread T into a loop to beheld between the thumb and index finger of one hand, the loop being positioned around the thread guide 1, or holds a segment of the thread T between the thumb and index fingers of respective hands with the intervening portion of the thread T being positioned adjacent to the thread guide 1. The operator then slides the loop or the intervening portion of the thread T down, against the keeper 2 on the outside of the hook 21 until the thread T rests in the notch 37. The operator forces the thread T downwardly from the notch 37 into the through the groove 33. The thread T is then directed into a slot 32 where it is retained by the bight of the keeper 2. The free end of the hook 21 ischamfered so that the size of the aperture increases from the groove 33 to the slot 32,.as shown in FIG. 3, to facilitate the movement of the thread T from the groove 33 to the slot 32. Once the thread T is positioned in the slot 32, the angle of the chamfer, as shown in FIG. 3, does not allow the thread T be'be pulled back into the groove 33, where if the thread T is forced into the notch formed by the chamfer and the walls of the slot 33, the thread T will'be forced either downwardly along the walls of the slot 32 or upwardly along the chamfer, as is obvious from the drawing, to restrict the movement ofthe thread T to the slot 32. l

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclose disclosure relates to a preferred embodiment of my invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention, are intended to be included within the scope of the appended claims.

lclaim:

l. A sewing machine thread guide having self-threading means to allow for quick threading without actually passing a thread endwise through an opening in the guide, said selfthreading means comprising a post, a said post being bifurcated to define between bifurcations an upwardly open slot at the top portion of said post, one of said bifurcations being formed with a vertical groove opening towards said slot, a keeper formed as an element distinct from said post, said keeper being an elongate element substantially uniform in cross-sectional configuration along its length and in one portion bent into a rounded hook shape with substantially straight parallel limbs of different length extending therefrom, means securing the longest straight limb of said keeper in one bifurcation of said post with said hook portion extending above the top portion of said post while spanning said slot to define a thread accommodating aperture, the shortest limb of said keeper being disposed within the vertical groove in the opposite bifurcation of said post, the'free .end of said shortest limb of said keeper being spaced from the walls of said groove whereby a thread may be slid against an outer surface of said hook portion of said keeper into said groove throughv which the thread may be moved into said1thread accommodating aperture in which the thread is then retained by said keeper. said hook portion being formed to meet said grooved bifurcation of said post at an acute angle facilitating into introduction of a thread into said groove from the outside of said post, and said free end of said shortest limb of said'keepe r being chamfered to deter movement of the thread from said aperture ;into

said groove.

2. A thread guide according to claim] wherein a bottom surface of said post is provided with a threaded hole adapted to receive a screw to secure said post to a sewing machine, and a projection formed on said bottom surface and spaced from said threaded hole, said projection being adapted to .be received in a hole in said sewing machine to'position said post. 

1. A sewing machine thread guide having self-threading means to allow for quick threading without actually passing a thread endwise through an opening in the guide, said self-threading means comprising a post, a said post being bifurcated to define between bifurcations an upwardly open slot at the top portion of said post, one of said bifurcations being formed with a vertical groove opening towards said slot, a keeper formed as an element distinct from said post, said keeper being an elongate element substantially uniform in cross-sectional configuration along its length and in one portion bent into a rounded hook shape with substantially straight parallel limbs of different length extending therefrom, means securing the longest straight limb of said keeper in one bifurcation of said post with said hook portion extending above the top portion of said post while spanning said slot to define a thread accommodating aperture, the shortest limb of said keeper being disposed within the vertical groove in the opposite bifurcation of said post, the free end of said shortest limb of said keeper being spaced from the walls of said groove whereby a thread may be slid against an outer surface of said hook portion of said keeper into said groove through which the thread may be moved into said thread accommodating aperture in which the thread is then retained by said keeper, said hook portion being formed to meet said grooved bifurcation of said post at an acute angle facilitating into introduction of a thread into said groove from the outside of said post, and said free end of said shortest limb of said keeper being chamfered to deter movement of the thread from said aperture into said groove.
 2. A thread guide according to claim 1 wherein a bottom surface of said post is provided with a threaded hole adapted to receive a screw to secure said post to a sewing machine, and a projection formed on said bottom surface and spaced from said threaded hole, said projection being adapted to be received in a hole in said sewing machine to position said post. 